The present invention relates to a cosmetic composition comprising mineral water and one or more compounds selected from the group consisting of creatine, pyruvic acid, and carnitine, and cosmetically acceptable salt or ester thereof.
Cosmetic compositions containing mineral water, e.g., in the form of liposomes, have been reported for the purpose of hydrating the skin. See French Patent Applications 2,608,426 and 2,668,063. Others have reported the use of mineral water in cosmetic compositions to reduce the irritant side effects of active agents such as salicylic acid. See U.S. Pat. Nos. 5,690,946 and 5,997,885.
Carnitine is an amino acid that is synthesized endogenously in the liver from its amino acid precursors lysine and methionine. This water soluble amino acid is found in highest concentrations in the adrenal glands, skeletal, and cardiac muscle, and smaller concentrations are found in the kidneys and brain. This distribution of carnitine in the body reflects the utilization of fatty acids by the tissues as a source of energy. Carnitine functions as a biocatalyst to carry long and medium length chain fatty acids across the cell wall and into the mitochondria where fats are metabolized for energy production. The absence of proper levels of carnitine in the cells may result in poor metabolism of fatty acids which can cause buildup within the cell and its surroundings to eventually lead to elevated blood fat and triglyceride levels. During the last decade, carnitine has seen increase use for muscle efficiency since fatty acid oxidation within the mitochondria is the muscle""s major source of energy. Carnitine is also used to improve fat metabolism and to reduce blood triglycerides. See, e.g., Bremer, J. xe2x80x9cCarnitine, Metabolism and Functionsxe2x80x9d Physiology Review. 63:1420-1480 (1983); Opie, L. H. xe2x80x9cRole of Carnitine in Fatty Acid Metabolism of Normal and Ischemic Myocardiumxe2x80x9d, Am. Heart Journal, 3:375-377 (1974); and Stryer, L. xe2x80x9cBiochemistryxe2x80x9d, 3rd ed., (1988, W. H. Freeman and Company, New York).
Creatine is synthesized in the liver and is supplemented by a diet of meat and fish. Ninety-five percent of the body""s creatine supply is found in the skeletal muscles. Creatine, which is converted into creatine phosphate within cells, increases the availability of energy to the cell in the form of adenosine triphosphate (ATP). Cells rely on energy produced in the Krebs cycle from the dephosphorylation of ATP to adenosine diphosphate (ADP). Creatine phosphate can then donate a phosphate group to ADP, recreating ATP and, thus, extending the energy generating biochemical pathways within cells. See, e.g. Balsom, P. D., et al. xe2x80x9cCreatine in humans with special reference to creatine supplementationxe2x80x9d, Sports-Med., 18(4):268-280 (1994) and Stryer, L. xe2x80x9cBiochemistryxe2x80x9d, 3rd ed., 1988, W. H. Freeman and Company, New York.
Pyruvate, the key glycolytic intermediate of all mammalian cells, is created during the metabolism of carbohydrates and protein. In addition to being formed in the body, pyruvate is present in foods including red apples, cheese, and red wine. The oxidation of pyruvate in the Krebs cycle provides cells with the bulk of adenosine triphosphate (ATP) used to maintain homeostasis. In cells with high energy charge, coenzyme A (CoA) is acylated as acetyl-CoA which activates pyruvate carboxylase, directing pyruvate toward gluconeogenesis. However, when energy is low in the cell, CoA is not acylated and pyruvate is preferentially oxidized via pyruvate dehydrogenase to CO2 and H2O. Through its role as an energy source pyruvate has been suggested to aid weight loss efforts and exercise endurance. See, e.g., Stanko, R. T., Tietze, D. L., and Arch, J. E. xe2x80x9cBody composition, energy utilization, and nitrogen metabolism with a 4.25-MJ/d low-energy diet supplemented with pyruvate,xe2x80x9d Am J Clin Nutr, 56(4), 630-635 (1992) and Stryer, L. xe2x80x9cBiochemistryxe2x80x9d, 3rd ed.(1988, W. H. Freeman and Company, New York).
In one aspect, the invention features a cosmetic composition comprising mineral water and one or more compounds selected from the group consisting of creatine, carnitine, and pyruvic acid, and cosmetically acceptable salts thereof, wherein the mineral water has a mineralization of at least about 200 mg/L (e.g., from about 300 mg/L to about 1000 mg/L).
In one embodiment, the invention features a topical cosmetic composition comprising (i) mineral water, (ii) a compound selected from the group consisting of creatine, carnitine, and pyruvic acid, and a cosmetically acceptable salt or ester thereof, and (iii) a cosmetically-acceptable topical carrier, wherein the mineral water has a mineralization of at least 200 mg/L.
In one embodiment, the composition further comprises at least one nutrient or a skin-conditioning agent selected from the group consisting of an emollient and a humectant.
In one embodiment, the invention also features methods of topically administering such compositions. The compositions of the present invention can enhance the uptake of oxygen, water, and nutrients into the skin (e.g., skin cells), enhance skin cell metabolism, reduce the loss of skin firmness and elasticity, and/or have a reduced incidence of eye irritation.